This invention relates to fuel tanks and oil tanks on industrial vehicles such as forklift trucks. More particularly, it relates to an air breather provided for fuel tanks and oil tanks.
In general, fuel and oil tanks are provided with air breathers in order that the fuel or oil to be stored in the tanks can be smoothly introduced into and discharged out of the tanks. Heretofore, as the construction for such an air breather, an air-breathing through-hole was formed in an oil filler cap applied to an oil filler opening. As far as the Applicant is aware, there is no literature or publication disclosing the aforementioned construction of an air breather device for tanks, but a construction for air breather devices used in industrial vehicles so far produced by the Applicant for company use is shown in FIG. 1.
This figure is a sectional view showing a prior-art example wherein a retainer 9 is projectedly mounted to the top of a main body 8 of the tank and a cap 9a is removably mounted to the foremost opening portion of the retainer. A rubber seal 9c is fitted to the inside of the cap 9a. The rubber seal 9c and the cap 9a are respectively provided with air breather through-holes 9d and 9b in communication with each other.
In the case of the air-breather device in which the air-breather through-holes are formed in the oil filler cap as described hereinabove, the fuel or oil in the tank 8 can leak into the engine compartment by way of the air-breather through-hole 9d if the vehicle should turn over. In particular, the lift truck may catch on fire should the fuel leak into the engine compartment which is an especially dangerous possibility.